Immediate, Delayed and Dual-Contact Reactivity to Common Contact Urticariogens in Patients with Chronic Spontaneous Urticaria: A Study in Serbia

Background: Multiple studies have suggested that chronic spontaneous urticaria (CSU) may be an autoimmune condition occurred in a substantial proportion of cases, but it is important to identify the potential triggers of the disease. There is no study in which the authors tried to answer the question of whether patch testing to common contact urticariogens should be routinely done in patients with CSU. Objectives: We assessed urticarial, eczematous, and dual contact reactivity in patients with CSU to common contact urticariogens, the frequency and etiology, and compared with patients suffering from atopic dermatitis (AD) and healthy non-atopic persons. Methods: All consecutive patients with chronic urticaria (CU) orADreferred to us fromVojvodina province (Serbia) betweenNovember 2015 and May 2017, and healthy volunteers were recruited. Contact reactivity was defined as a positive patch-test to at least one of 15 well-known contact urticariogens. Results: During the study period, 155 patients with CU and 100 patients with AD were referred, and 100 healthy control volunteers were also recruited. Among them, 90 patients with CU, 75 with AD and 70 healthy volunteers gave their written informed consent. Moreover, those who did not fulfill the proposed criteria were excluded. Finally, the patients were divided into three groups: the CSU group included 28 patients with current CSU selected from 73 patients with CU; the Group A included 60 persons with current extrinsic AD, and the Group C included 50 healthy non-atopic persons. In all groups, benzoin, cinnamic acid, benzoic acid, and Peru balsam were among the top five allergens in contact-urticarial response, whereas nickel and cinnamic acid were among the top three in eczematous response. The rates of urticarial, delayed, anddual contact reactivity to at least one allergen did not significantly differ [(2-boot = 1.410; P = 0.480). (2-boot = 1.341; P = 0.527) and (2-boot = 0.316; P = 0.907), respectively] among different groups. The difference was detected to benzoin urticarial reactivity (2-boot = 8.487; P = 0.016): in the CSU or AD groups, it was significantly higher than the C group (P = 0.025 and 0.010, respectively). A significant difference was detected in female urticarial reactivity to benzoin (2-boot = 6.998; P = 0.031): in the group AD, it was higher than the C group (P = 0.018). Conclusions: This could be of the first studies in which the researchers tried to answer the question of whether patch testing to common contact urticariogens should be routinely proposed in patients with chronic spontaneous urticaria. The authors suggest that more investigations have to be designed through multicentric research.